Pesky Punctuation: Joining Independent Clauses

Now we’ve covered the basics and have explored terminal marks, it’s time to turn our attention to the second use of punctuation: joining clauses. There’s a lot of ground to cover, so this post focuses on joining independent clauses. Dependent clauses will be brought into the mix in the next post.

As a quick review, a clause is a group of words that contains both a subject and a verb, and an independent clause is one that can stand alone as a complete sentence.

>> Don’t miss the other posts in the series: The Basics, Terminal Marks, Joining Dependent & Independent Clauses, and Phrases & Omissions <<

Joining two independent clauses forms a compound sentence, and these may be connected using a comma, a colon, a semicolon, or a dash. Which of these four marks is appropriate depends on the type of bond, meaning how the two clauses are to be joined. There are four types of bonds, so there are four ways to join independent clauses. And this is done with commas, colons, semicolons, or dashes—basically, everything we all struggle with. Don’t worry! I’ll break it down.

BOND #1: Colons, Semicolons & Dashes

Sometimes, independent clauses can be joined by punctuation alone. As long as there is no conjunction or adverb in the way—and if replaced with a period, both clauses would still form a complete sentence—form the bond using a colon, a semicolon, or a dash.

Colons (:). These are used when the second clause introduces an element (or series) that further illustrates or explains something stated in the first clause. The first word following a colon is not capitalized unless it is a proper noun, or if it introduces two or more sentences, dialogue, or a question or quotation.
- “For the exam, students are asked to bring their supplies: a ruler, a calculator, an eraser, and two pencils.”
- “Guests had a choice of three dishes: fish, chicken, or pasta.”
Semicolons (;). These are used when no conjunction joins the clauses and help illustrate a close relationship between the two. Unlike a colon, it does not add to the first clause, rather it almost continues the thought. The first word following a semicolon is not capitalized unless it is a proper noun
- “She needed a new watch to track and reach her fitness goals; no mere step-counter would do.”
- “An accomplished painter, Mark decided to turn his efforts elsewhere; his real passion was dance.”
Dashes (—). Some love a good ol’ em dash—some don’t. As with colons and semicolons, em dashes amplify the preceding clause and are particularly effective at showing a sudden change in tone. Versatile, these dashes can be used in places of parentheses, commas, and colons.
- “Guests had a choice of three dishes—fish, chicken, or pasta.” (Colon could also be used.)
- “My dogs—Kylie, Roxy, and Charlie—are all very well-behaved.” (Parentheses could also be used.)
- “Mr. Williams—the board superintendent—upheld the ban on cell phones during school hours.” (Commas could also be used.)
You may have heard of the en dash, although they are rare in creative writing. En dashes are slightly shorter than an em dash and are used to connect numbers and words: 2000–2020, Paris–London, the score was 5–3.

BOND #2: Adverbs

There are many types of adverbs, but by definition, an adverb is a word that modifies a verb, an adjective, or another adverb. They express manner, place, time, frequency, and degree. A lot of -ly words are adverbs, but they are also words like indeed, therefore, thus, and nevertheless.

When an adverb is used to join two independent clauses, a semicolon goes before the adverb and a comma will typically (though not always) follow the adverb. (I’ve used italics to indicate the adverb in each sentence.)

“Fresh lemons are essential when making a meringue; indeed, it will taste too sour otherwise.”
“The dog was proud to wear its holiday bow tie; however, the cat would not stop pawing at theirs.”
“Sandra normally loved skateboarding; lately, that had not been the case.”

As with short adverbial phrases, no comma is needed if thus or therefore is used as the transition is abrupt and adequately sets off what follows by itself.

“Thus the jury stated their decision.”
“Therefore there are no more plums.”

BOND #3: Transitional Expressions

A word or phrase that shows how two clauses are related in meaning is called a transitional expression: in addition, for example, as stated, namely. As with adverbs, a semicolon precedes the transitional expression and a comma will follow. (I’ve used italics to indicate the transitional expression in each sentence.)

“I love a lot of seafood; namely, lobster and crab.”
“There are many ways to incorporate exercise into your summer evenings; for example, you could go on a family walk or bike ride.”

BOND #4: Coordinate Conjunctions

A common and effective way to recall coordinate conjunctions is with FANBOYS—for, and, nor, but, or, yet, so. When two independent clauses are joined by one of these words a comma is placed before the conjunction. (I’ve used italics to indicate the conjunction in each sentence.)

“There was a big snowstorm last night, so the bus was an hour late.”
“My days are busy, yet I always find time to do a little reading.”

However, the comma may be left out when the two clauses are short and there is little chance readers will be confused.

“There was a big snowstorm and the bus is late.”
“I like tea but my boyfriend likes coffee.”

A NOTE ON COMMAS

Why are commas (on their own) not included in any of these bonds? Because by themselves commas are insufficient to join two independent clauses. This only works when the series of independent clauses all have the same subject—“She came, she saw, she conquered”—otherwise, you end up with a run-on sentence.

The other mistake writers often make with the comma is confusing compound sentences and compound predicates. A compound predicate is a single clause in which one subject governs two verbs. (For example, “Joan went shopping then cooked dinner.”) A comma goes before the compound predicate if, but only if, there is a chance readers may be confused as to the relationship between the two clauses. (For example, “Joan will go shopping tomorrow, and on Sunday will cook roast for dinner. Without the comma, “tomorrow and on Sunday” could be read as one unit of thought.)

Phew! Take a breather, drop any questions in the comments below, and get ready for the next post in the Pesky Punctuation series: Joining Dependent and Independent Clauses.

Until then, keep creating!